As high bitrate communication and large data volume increases in popularity, the strive for delivering and designing corresponding delivery systems is intensified. At the same time, the available bandwidth spectrum is becoming progressively smaller. As bandwidth is a proportional factor in defining data capacity, it is evident that all techniques aiming at enhancing bandwidth efficiency are of high importance. The industry has since the beginning of cellular communication developed and pushed for new spectrum efficient communication standards going from the very first generation analog systems such as the AMPS (Advanced Mobile Phone System), TACS (Total Access Communication System) and NMT (Nordic Mobile Telephone) through digital systems such as D-AMPS (Digital AMPS) and GSM (Global System for Mobile communications) defining second generation systems, to the third generation systems like CDMA (Code Division Multiple Access) and W-CDMA (Wideband CDMA) as well as fourth generation systems such as LTE (Long Term Evolution).
For example, LTE Advanced as it is being defined, is one of the standards that calls for even higher bitrates. Together with high bitrates, aggregation of frequency bands, where available, is also a new theme not yet proposed in other standards. To be able to keep up with the spectrum efficiency at the same time, this calls for a new way of building practice with distributed active antenna elements. Other names of this approach are for example active antennas (AA), integrated antennas (IA), or Intelligent Active Antennas (IAA).
Implementing such active antennas is a complex task that requires careful design and assembly. It would be of great benefit if building and deploying active antennas were to be simplified and reduced in complexity.
U.S. Pat. No. 5,912,927 presents a multi-channel transceiver with an adaptive antenna array. The presented system utilizes digital signal combining and splitting to reduce losses and signal degradation. However, the presented solution is a mere splitting/combining of signals and does not provide any significant advantage to active antennas.